Hi learned folk.
I have a Mini4 Pro with the RC 2 controller.
Im going to to be travelling internationally and luggage space is at a premium so I cannot take a laptop.
I have seen talk of using the DJI RC as an intermediary unit to transfer images to a USB-C external drive.
Transfer from the drone is way too slow, can you put the SD card from the drone into the RC unit and copy from there?
Has anybody done this? or have any ideas please.
Ta
You can use a card reader, attached to the USB of your phone, to copy from the card. Then you can attach the external drive to copy them to that.
Not tried it myself but you could plug the HD into the USB C on the controller and put the SD card into the controller and copy across to that.
As Ozonevibe said works great
Its worth getting a decide adapter if your concerned about transfer speeds.
SanDisk Extreme PRO Card Reader works well
Transfer to what?
If I’m not with my card reader, I’ll fire up DJI Fly on my iPhone and set the drone into Quick Transfer mode. It’s not as fast as reading direct from the card but fine for me.
Probably …
Don’t come at me with your cheek! 
You can’t be copying direct to a drive from the drone, so I’m guessing it’s via a laptop.
But ..
.. hence my recommendation to copy via the phone in two stages.
But I want to know what it’s transferring to slowly! I said laptop as I’m guessing that’s what they are using at the moment to transfer but want confirmation.
I know they can’t use the laptop on holiday so that’s why I offered using the DJI Fly app on a phone.
I read it as that method was what was slow.
… also wastes battery that then needs additional recharging .. and the main reason I’ve always taken the card out of my drones to copy the contents.
I’m sure I’ve read that, on some newer drones, a powered USB connection can access the SD card in the drone without turning it on .. which makes a lot of sense .. but doesn’t help if copying to a phone, of course.
Hi I would normally pull the images off via a laptop, but Im travelling round Europe on trains, and busses for 3 weeks with a rucksack, so a laptop is just too much to carry/lose, But using the phone or maybe an iPad may work. with a reader.
Or one of those Sandisk extreme SSD usb-c things
Given what i understand as your travel constraints i would
1 pull card from drone
2 put card in a decent spec reader
3 tranfer to phone
4 transfer to bulk storage.
Off the top of my head the app maxs out at 30Mb/s via wifi
Average usb adapter hits about 70Mb/s ish if not way more. My ssd external hits 700-800 ish transfering it back to windows.
Again, just off the top of my head so dont quote me.
EDIT sandisk extreme pro usb c ssd work great. Small and quick.
just tried my RC controller with the screen that came with my Mini 3 pro - it will not see a SSD plugged into the USBC port so you cant copy from the SC Card to the SSD - pity that.
128GB cards are only around £12 quid.
Just buy a few more cards and then you don’t need to transfer anything anywhere until you get back home?
Zero luggage space required 
Ha, I would but I have learnt the hard way that copying your data off the drone after every flight, or at least at the end of the day is good data hygiene.dont embarrass me by asking how I know this 
For proper hygiene use the cloud
Unless you are carrying 2 SSD drives
i use these for DSLR camera sd cards and one in the drone case with micros sd cards (keep topping up with cards)
If speed is more the goal, would a USB C hub (with USB 3 ports and a matching card reader) remove using the phone as a go-between?
Just one copy operation and less faff.
Downside is you’ll not have the copy on the phone, but bonus is it could charge phone at same time. Still smaller than a laptop!
Easy, you plug the ssd into the DJI RC controller via the usb c host connector ( not the usual usb c charging port). Your controller will detect the external drive. Search YouTube for videos on how to do this 
